The present invention relates to an improved base assembly for a fluorescent lamp having a glass envelope of U-shape, comprising two bases provided with contact pins and an oblong spacer member.
In order to ensure the spacing of the two bases or of the two bent lamp ends, respectively, it is well known to provide each base with a metal clamp around its circumference in such manner that the flaps of the respective clamp point towards each other in the direction of the connection line of the two bases. The two clamps are then interconnected by means of a crossbar which is placed with its respective ends between the pair of clamp flaps and is riveted in this place (Elektronorm (1963), No. 2, page 59).
Another type of base assembly for U-shaped fluorescent lamps has been disclosed in U.S. Pat. No. 3,579,174. This structure provides a notch in the circumference of each base, the notches facing one another and extending in the plane common to the base pins. The notched bases are interconnected by a bar which has a groove at its ends. The grooved ends engage in the respective notch at the base circumference. The assembly is then sealed with cement to the lamp ends.
DT-OS No. 21 01 967 discloses a bracket with semicircularly or circularly curved ends as the spacer member; the straight-line portion of the bracket is passed through a notch in the circumference of the respective base cap which is flush with the base pins so that the curved ends of the bracket come to lie internally of the base cap. A ring-shaped binding agent (cement ring) is introduced into the base caps and the whole assembly is sealed to the lamp ends by heating.
It is the object of the present invention to minimize breakage of U-shaped lamps during fabrication by using an assembly which permits automation and is economical.